• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.219-220
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• 2009

Many surveillance cameras used in security system are controlled with RS-485 communication protocol. In this situation, if RS-485 connection can be replaced with wireless connection using sensor network technology, an installation will become ease because of no wired connection and also a deployment of cameras will become free. This paper explains about the design of wireless sensor node and the necessary implementation for an operation, which can be replacing RS-485 connection for the development of CCTV control system based on wireless sensor network. The hardware platform of sensor node was designed based on MicaZ and the software was developed based on TinyOS. To control surveillance cameras deployed on wide area, the supporting of multi-hop also was implemented. With the result of experiment deploying on real environment, it was revealed that the controller could control cameras quickly with wireless.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.101-105
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• 1997

This paper presents the worst-case time-delay in CAN(Controller Area Network) system through the mathematical model. Time-delay in the CAN system is devided into a generation delay, a transmission delay and a delivery delay. This paper also measures the performance represented in terms of the number of station, transmission speed, data size etc. by using the computer simulation.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.677-680
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• 2003

In this paper, the analysis of practical end-to-end delay in worst case is performed for distributed control system considering the implementation of the system. The control system delay is composed of the delay caused by multi-task scheduling of operating system, the delay caused by network communication, and the delay caused by the asynchronous between them. Through simulation tests based on CAN(Controller Area Network), the proposed end-to-end delay in worst case is validated. Additionally, online clock synchronization algorithm is proposed here for the control system. Through another simulation test, the online algorithm is proved to have better performance than offline one in the view of network bandwidth utilization.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.1063-1068
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• 2008

BACnet(Building Automation and Control Networks) is a standard data communication protocol specifically designed for building automation and control systems, BACnet provides six options for data link layer protocols and these six data link layer options can be applied with various wired transmission media. Recently wireless technology prevails in automation area. ZigBee is an IEEE 802.15.4 based standard communication protocol for low-rate wireless personal area networks. In this study, we propose a BACnet over ZigBee model that adopts ZigBee communication channel as a wireless data link layer protocol in a BACnet-based communication network system. The technology proposed in this paper can expand the BACnet application using the advantages of wired and wireless integrated network solution.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.4
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• pp.480-487
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• 1999

In this paper we propose a neural network precompensated PID(NNP PID) controller for load frequency control of 2-area power system. While proportional integral derivative(PID) controllers are used in power system they have many problems because of high nonlinearities of the power system So a neural network-based precompensation scheme is adopted into a conventional PID controller to obtain a robust control to the nonlinearities. The applied neural network precompen-sator uses an error back-propagation learning algorithm having error and change of error as inputand considers the changing component of forward term of weighting factor for reducing of learning time. Simulation results show that the proposed control technique is superior to a conventional PID controller and an optimal controller in dynamic responses about load disturbances. The pro-posed technique can be easily implemented by adding a neural network precompensator to an existing PID controller.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.121-127
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• 2004

The controller area network(CAN) was originally developed to support cheap and rather simple automative applications, However, because of the its performance and low cost, it is also being considered in automated manufacturing and process control environments to interconnect intelligent devices, such as modem sensors and actuators. This paper presents a new application technology of the developed CAN control modules for the automated doors in building automation system Key pad and RF methods are used to open and close the automated door by the slave CAN module with CAN Protocol. BAS application technology of CAN field bus modules is also presented firstly in our nation.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2296-2300
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• 2005

This paper deals with the real-time message network system by a CAN (controller area network) based on the real-time distributed control scheme to integrate actuators and sensors in a humanoid robot. In order to apply the real-time distributed processing for a humanoid robot, each control unit should have the real-time efficient control method, fast sensing method, fast calculation and real-time valid data exchange method. Moreover, the data from sensors and encoders must be transmitted to the higher level of control units in maximum time limit. This paper describes the real-time message network system design and the performance of the system.

• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.109-117
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• 2020

In this paper, we analyze LADN(Local Area Data Network) that provides high throughput, low latency and service localization for 5G wireless networks and propose an enhanced control protocol design for LADN in 5G wireless networks. The concept of LADN is newly introduced in 3GPP 5G communication system and the LADN is a data network to which the UE(User Equipment) can connect with a specific LADN session only when the UE is located in a certain service area. If the LADN information between the UE and core network is not identical, the LADN session cannot be properly established. The proposed approach promplty synchronizes the LADN information between the UE and core network by using the specific registration procedure and appropriately establishes the LADN session, when the establishment of the LADN session is failed. Consequently, the proposed enhanced control protocol design(ECP) can prevent unnecessary signalling overhead and communication delay for LADN in 5G wireless networks.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.1058-1064
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• 2004

This paper presents a distributed precedence queue mechanism to resolve unexpected transmission delay of a lower priority transaction in a CAN based system, which keeps a fixed priority in data transaction. The mechanism is implemented in the upper sub-layer of the data link layer(DLL), which is fully compatible with the original medium access control layer protocol of CAN. Thus the mechanism can be implemented dynamically while the data transactions are going on without any hardware modification. The CAN protocol was originally developed to be used in the automotive industry, and it was recently applied for a broader class of automated factories. Even though CAN is able to satisfy most of real-time requirements found in automated environments, it is not to enforce either a fair subdivision of the network bandwidth among the stations or a satisfactory distribution of the access delays in message transmission. The proposed solution provides a superset of the CAN logical link layer control, which can coexist with the older CAN applications. Through the real experiments, effectiveness of the proposed mechanism is verified.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.195-198
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• 2001

본 논문에서는 최근 그 응용이 증가하고 있는 CAN통신 프로토콜을 이용하여 차량내 network개념을 도입하여 차내 각종 전기신호와 센서 입출력을 제어하는 통합 시스템의 개발에 관한 것을 간략히 기술한다. CAN시스템은 최대 1Mbps의 전송 비트율과 에러검출 및 에러영향의 시스템 내로의 한정 등의 기능이 뛰어난 높은 레벨의 통신 안정성을 가지면서 분산 실시간 제어를 효율적으로 지원하는 serial bus communication프로토콜의 하나이다. 본 연구에서 개발된 시스템은 4개의 독립 제어시스템과 관련 소프트웨어로 구성되어 있으며. 각각의 제어시스템간의 정보의 교환은 CAN통신 프로토콜에 안정적으로 이루어지며 자동차의 고급화와 함께 향후 실용화가 기대된다.